In a sample of double-stranded DNA, 12% of the nitrogenous bases are guanine (G). What percentage of the nitrogenous bases in the sample are cytosine

12%

Explanation:

The percentage of Guanine and Cytosine in DNA are equal to each other, as one molecule of guanine bonds with one molecule of cytosine.

Conversely, the percentage of adenine and thymine in DNA are equal to each other.

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.

the dissolution of polymer can be thermodynamically described in 2 steps.